JP2021031541A - Curable composition, cured product and method for forming insulating film - Google Patents

Abstract

To provide: a curable composition which enables the formation of a cured product having a low dielectric constant, low dielectric loss tangent, high heat resistance, excellent elongation and excellent tensile strength and which has excellent film forming properties; a cured product of the curable composition; and a method for forming an insulating film with the use of the curable composition.SOLUTION: This curable composition contains a modified maleimide compound (A), a radical generator (C) and a thiol compound (D). Preferably, the curable composition contains a photo-radical generator (C1) as the radical generator (C). Preferably, the curable composition further contains a protonic acid (E).SELECTED DRAWING: None

Description

The present invention relates to a curable composition, a cured product, and a method for forming an insulating film.

In recent years, communication devices such as mobile phones have been increasing in frequency. Therefore, the insulating film that insulates the metal wiring of communication equipment is also required to have a higher frequency.
Here, the higher the frequency, the higher the transmission loss, and when the transmission loss increases, the electric signal is attenuated. Therefore, it is required to reduce the transmission loss as a measure for increasing the frequency.

In order to reduce transmission loss, a technique for forming an insulating film using a material having a low dielectric constant and a dielectric loss tangent is disclosed (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2004-87639

However, the technique of Patent Document 1 is a technique using a resin composition having a specific structure, specifically, a resin composition containing a cross-linking component represented by the formula (1) described in Patent Document 1. Techniques using other compositions are required.
It should be noted that support for higher frequencies is also required for electrical and electronic devices other than communication devices, such as network-related electronic devices such as servers and electronic devices such as computers.

Further, in the manufacture of electric / electronic devices, since an insulating film is often formed from a composition and then heated to further form a member such as a wiring, the insulating film is also required to have heat resistance.
When the insulating film is formed from the composition, the insulating film can be easily formed according to the coating method. Therefore, the composition can be applied to the coating method, that is, has excellent film forming property in the coating method. Is desirable.

Further, as represented by applications such as panels for flexible display devices, there are increasing cases where the insulating film is required to have durability against deformation such as elongation. Therefore, for a composition capable of forming an insulating film, it is required to be able to form a film having excellent elongation and tensile strength.

The present invention has been made in view of the above problems, and can form a cured product having a low dielectric constant and dielectric loss tangent, excellent heat resistance, elongation, and tensile strength, and has excellent film forming property. It is an object of the present invention to provide a sex composition, a cured product of the curable composition, and a method for forming an insulating film using the curable composition.

The present inventors have prepared a curable composition containing a radical generator (C) and a thiol compound (D) together with a maleimide-modified compound (A) having a radically polymerizable group having a specific structure including a maleimide skeleton. We have found that a cured product having a low rate and dielectric tangent, excellent heat resistance, elongation, and tensile strength is provided, and that the film forming property is excellent, and the present invention has been completed.

で表される基を１以上有し、
式（ａ１）で表される基が、マレイミド変性化合物（Ａ）における脂肪族炭化水素基中又は芳香族基中の炭素原子に結合しており、
式（ａ１）中、Ｒ^ａ０１及びＲ^ａ０２は、それぞれ独立に、水素原子、炭素原子数１以上６以下のアルキル基、炭素原子数３以上８以下のシクロアルキル基又は炭素原子数６以上１２以下のアリール基である、硬化性組成物である。 A first aspect of the present invention comprises a maleimide-modified compound (A), a radical generator (C), and a thiol compound (D).
The maleimide-modified compound (A) has the following formula (a1):

It has one or more groups represented by
The group represented by the formula (a1) is bonded to a carbon atom in the aliphatic hydrocarbon group or the aromatic group in the maleimide-modified compound (A).
In the formula (a1), R ^a01 and R ^a02 independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, a cycloalkyl group having 3 or more and 8 or less carbon atoms, or 6 or more and 12 or less carbon atoms. It is a curable composition which is an aryl group of.

A second aspect of the present invention is a cured product of the curable composition according to the first aspect.

A third aspect of the present invention includes a coating step of applying the curable composition according to the first aspect to the insulating film forming portion to form a coating film.
It is a method of forming an insulating film, which includes a curing step of curing the coating film.

According to the present invention, a curable composition having a low dielectric constant and dielectric loss tangent, capable of forming a cured product having excellent heat resistance, elongation, and tensile strength and having excellent film forming property, and the curable composition. It is possible to provide a cured product of a product and a method for forming an insulating film using the curable composition.

で表される基を１以上有する。式（ａ１）で表される基は、マレイミド変性化合物（Ａ）における脂肪族炭化水素基中又は芳香族基中の炭素原子に結合している。
式（ａ１）中、Ｒ^ａ０１及びＲ^ａ０２が、それぞれ独立に、水素原子、炭素原子数１以上６以下のアルキル基、炭素原子数３以上８以下のシクロアルキル基、又は炭素原子数６以上１２以下のアリール基である。 << Curable composition >>
The curable composition contains a maleimide-modified compound (A), a radical generator (C), and a thiol compound (D).
The maleimide-modified compound (A) has the following formula (a1):

It has one or more groups represented by. The group represented by the formula (a1) is bonded to a carbon atom in the aliphatic hydrocarbon group or the aromatic group in the maleimide-modified compound (A).
In the formula (a1), R ^a01 and R ^a02 independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, a cycloalkyl group having 3 or more and 8 or less carbon atoms, or 6 or more and 12 carbon atoms. The following aryl groups.

The curable composition containing the maleimide-modified compound (A) and the radical generator (C) has good film-forming properties, low dielectric constant and dielectric loss tangent, and excellent heat resistance. give.
Further, when the curable composition contains the thiol compound (D) together with the maleimide-modified compound (A), the curable composition can be used to form a cured product having excellent elongation and tensile strength.

The curable composition is preferably used for forming an insulating film. Typically, the curable composition is used in an electrical / electronic device having metal wiring to form an insulating film that insulates the metal wiring.
The electrical and electronic devices are not particularly limited, and communication devices such as mobile phones, network-related electronic devices such as servers, electronic devices such as computers, and particularly semiconductor components possessed by these devices, specifically, A semiconductor package called a wafer level package can be mentioned.
These electric / electronic devices have metal wiring made of a metal such as copper or an alloy on a substrate for the electric / electronic device. Examples of the substrate for an electric / electronic device having metal wiring include a silicon substrate and a substrate on which various layers and members are provided on the silicon substrate.
This metal wiring and other metal wiring or conductive member are insulated by an insulating film formed of a curable composition.
By using a curable composition containing a component described later, an insulating film having a low dielectric constant and a low dielectric loss tangent (tan δ) can be formed. Therefore, the curable composition containing the components described later is suitable as an insulating film for insulating the metal wiring of an electric / electronic device using a high frequency signal. In addition, in this specification, "high frequency" means a frequency of 3GHz or more.
Further, since an insulating film having excellent heat resistance can be formed, the curable composition can be used, for example, for forming an insulating film in an electric / electronic device in which another member is formed by heating after forming the insulating film with the curable composition. Can be used.
Further, the curable composition provides a cured product having excellent elongation and tensile strength. Therefore, the insulating film formed by using the curable composition can be suitably used in applications where bending stress or tensile stress is applied, such as a panel for a flexible display device.
The curable composition is excellent in film forming property by the coating method, that is, when the film is formed by the coating method, there is no crack and crystal formation, there is no tack (stickiness), and the compatibility of the components is also good. Therefore, the insulating film can be formed by a coating method, which is an easy method.

Hereinafter, essential or optional components contained in the curable composition will be described.

（式（ａ１）中、Ｒ^ａ０１及びＲ^ａ０２は、それぞれ独立に、水素原子、炭素原子数１以上６以下のアルキル基、炭素原子数３以上８以下のシクロアルキル基または炭素原子数６以上１２以下のアリール基である。） <Maleimide-modified compound (A)>
The curable composition contains a maleimide-modified compound (A) having one or more groups represented by the following formula (a1) in one molecule. The group represented by the following formula (a1) is bonded to a carbon atom in an aliphatic hydrocarbon group or an aromatic group contained in the maleimide-modified compound (A). The maleimide-modified compound (A) may be a maleimide-modified resin (A1) which is a polymer having one or more groups represented by the following formula (a1) in one molecule, and is represented by the following formula (a1). It may be a maleimide monomer (A2) which is a non-polymer having one or more groups to be formed in one molecule. The maleimide-modified compound (A) is composed of only the maleimide-modified resin (A1) or the maleimide-modified resin (A1) and the maleimide-modified compound because it is easy to form a cured product having excellent mechanical properties, heat resistance, chemical resistance, and the like. It is preferably in combination with the monomer (A2).

(In the formula (a1), R ^a01 and R ^a02 are independently hydrogen atoms, alkyl groups having 1 or more and 6 or less carbon atoms, cycloalkyl groups having 3 or more and 8 or less carbon atoms, or 6 or more and 12 carbon atoms. The following aryl groups.)

^{The alkyl groups having 1 or more and 6 or less carbon atoms as R a01} and R ^a02 in the formula (a1) may be linear or branched, and specific examples thereof include a methyl group, an ethyl group, and an n-propyl group. , N-butyl group, n-pentyl group, n-hexyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group, isopentyl group, neopentyl group, tert-pentyl group and isohexyl group.
^{Specific examples of the cycloalkyl group having 3 or more and 8 or less carbon atoms as R a01} and R ^a02 in the formula (a1) include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, and a cyclohexyl group.
^{Specific examples of the aryl group having 6 to 12 carbon atoms as R a01} and R ^a02 in the formula (a1) include a phenyl group, a biphenyl group, a 1-naphthyl group and a 2-naphthyl group.
It is preferable that both ^{R a01} and R ^a02 in the formula (a1) are hydrogen atoms. When both R ^a01 and R ^a02 are hydrogen atoms, the polymerizability is excellent, so that a curable composition having excellent curability can be obtained. When both R ^a01 and R ^a02 are hydrogen atoms, the group represented by the formula (a1) is an unsubstituted maleimide group.

The bonding position of the group represented by the formula (a1) in the maleimide-modified compound (A) is not particularly limited as long as it does not impair the object of the present invention. When the maleimide-modified compound (A) is a maleimide-modified resin (A1), in the maleimide-modified resin (A1), the group represented by the above formula (a1) is the main chain and / or side of the maleimide-modified resin (A1). It is preferable that the carbon atom in the aliphatic hydrocarbon group or the aromatic group in the chain is bonded to a carbon atom located at a position other than the terminal of the main chain of the maleimide-modified resin (A1). That is, the maleimide-modified resin (A1) is a carbon atom in an aliphatic hydrocarbon group or an aromatic group in the main chain and / or side chain of the resin, and is a main chain terminal of the maleimide-modified resin (A1). It is preferable that the hydrogen atom bonded to the carbon atom located at a position other than the above is substituted with a group represented by the formula (a1).
Examples of the resin that gives the maleimide-modified resin (A1) having such a structure include a polymer of a monomer having an unsaturated double bond. Examples of such resins include (meth) acrylic resins and polystyrene-based resins. In addition, in this specification, "(meth) acrylic" means both "acrylic" and "methacryl".
The "(meth) acrylic resin" is one or more monomers selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrylamide which may be an N-substituted product. It is a resin containing a structural unit derived from. The (meth) acrylic resin may contain a structural unit derived from a monomer other than (meth) acrylamide, which may be a (meth) acrylic acid, a (meth) acrylic acid ester and an N-substituted product.
The "polystyrene resin" is a resin containing a structural unit derived from styrene and / or a styrene derivative.
In the specification of the present application, it is derived from one or more monomers selected from the group consisting of (meth) acrylic acid, (meth) acrylic acid ester, and (meth) acrylamide which may be an N-substituted product. A resin containing a constituent unit and a constituent unit derived from styrene and / or a styrene derivative is treated as a (meth) acrylic resin for convenience.
In the present specification, the “side chain” means a molecular chain branched from the main chain. For example, when the resin is a (meth) acrylic resin, a carboxy group, an ester group, an amide group which may be N-substituted, or a methyl group bonded to the α carbon of the monomer of the (meth) acrylic resin. Is a side chain. When the resin is a styrene resin, the phenyl group bonded to the carbon atom derived from the carbon-carbon double bond of the monomer of the styrene resin and its derivative are side chains.

In the maleimide-modified resin (A1), the group represented by the above formula (a1) is a carbon atom in an aliphatic hydrocarbon group or an aromatic group in the main chain and / or side chain of the maleimide-modified resin (A1). Since it is bonded to a carbon atom located at a position other than the terminal of the main chain of the maleimide-modified resin (A1), the group represented by the formula (a1) is at least the side chain of the maleimide-modified resin (A1). It is a part.
For example, a carbon atom in an aliphatic hydrocarbon group or an aromatic group in the main chain of a maleimide-modified resin (A1) and located at a position other than the terminal of the main chain of the maleimide-modified resin (A1) may be added to the carbon atom. When the group represented by the formula (a1) is bonded, the maleimide-modified resin (A1) has a structure having an aliphatic hydrocarbon group or an aromatic group in the main chain, and the aliphatic in the main chain. Since the group represented by the formula (a1) is bonded to the carbon atom in the hydrocarbon group or the aromatic group, the group represented by the formula (a1) becomes a side chain of the maleimide-modified resin (A1). ..
When the group represented by the above formula (a1) is bonded to the carbon atom in the aliphatic hydrocarbon group or the aromatic group in the side chain of the maleimide-modified resin (A1), the maleimide-modified resin (A1) has a structure having an aliphatic hydrocarbon group or an aromatic group in the side chain, and is represented by the formula (a1) in the carbon atom in the aliphatic hydrocarbon group or the aromatic group in the side chain. Since the groups are bonded, the group represented by the formula (a1) becomes a part of the side chain of the maleimide-modified resin (A1).

In the maleimide-modified resin (A1), the carbon atom in the aliphatic hydrocarbon group or the aromatic group in the main chain and / or the side chain of the maleimide-modified resin (A1) is the maleimide-modified resin (A1). It suffices that the group represented by the above formula (a1) is bonded to a carbon atom located at a position other than the terminal of the main chain of. Further, a group represented by the above formula (a1) may be bonded to a carbon atom located at the end of the main chain of the maleimide-modified resin (A1).
Further, the group represented by the formula (a1) is preferably contained in the constituent unit of the resin.

The main chain of the maleimide-modified resin (A1) is not limited to these, but is preferably, for example, a main chain derived from a (meth) acrylic resin or a main chain derived from a polystyrene-based resin. Since the (meth) acrylic resin and the polystyrene-based resin have low dielectric constants and dielectric loss tangents, they are formed when the main chain is a main chain derived from the (meth) acrylic resin or a main chain derived from the polystyrene-based resin. It is possible to further reduce the dielectric constant and the dielectric loss tangent of the insulating portion.

The molecular weight of the maleimide-modified resin (A1) is not particularly limited as long as the effects of the present invention are not impaired, but the mass average molecular weight (Mw) is preferably 4000 or more, more preferably 5000 or more, and 10,000 or more. The above is more preferable. The molecular weight of the maleimide-modified resin (A1) is preferably 100,000 or less, more preferably 80,000 or less, as the mass average molecular weight (Mw).
In the present specification, the mass average molecular weight (Mw) is a measurement value obtained by gel permeation chromatography (GPC) in terms of polystyrene.

（式（ａ２）中、Ｒ^ａ０１及びＲ^ａ０２は、式（ａ１）中のＲ^ａ０１及びＲ^ａ０２と同様であり、
Ｒ^ａ１〜Ｒ^ａ６は、それぞれ独立に、水素原子、ハロゲン原子、炭素原子数１以上４以下のアルキル基、又は炭素原子数１以上４以下のアルコキシ基であり、Ｒ^ａ１とＲ^ａ５とは、互いに結合して−Ｏ−、−Ｓ−、−ＣＨ_２−、又は−ＣＲ^ａ７Ｒ^ａ８−を形成してもよく、Ｒ^ａ３とＲ^ａ４とは、互いに結合して炭素数６以上１２以下の環を構成してもよく、
Ｒ^ａ７及びＲ^ａ８は、それぞれ独立に、水素原子、炭素数１以上４以下のアルキル基又は炭素原子数１以上４以下のアルコキシ基である。）
で表されるジカルボン酸無水物とを縮合させて、下記式（ａ３）：

（式（ａ３）中、Ｒ^ａ０１及びＲ^ａ０２は、式（ａ１）中のＲ^ａ０１及びＲ^ａ０２と同様であり、Ｒ^ａ１〜Ｒ^ａ６は、式（ａ２）中のＲ^ａ１〜Ｒ^ａ６と同様である。）
で示される基を生成させる第１工程と、
第１工程で生成した、式（ａ３）で表される基を有する中間体化合物を加熱して、式（ａ３）で表される基を式（ａ１）で表される基に変換する第２工程と、を含む製造方法により製造することができる。 The method for producing the maleimide-modified compound (A) is not particularly limited. Specifically, the maleimide-modified compound (A) has a primary amino group in a raw material compound such as a resin having a primary amino group, and the following formula (a2):

(In the formula ^{(a2), R a01} and ^{R a02} are the same as ^{R a01} and ^{R a02} in the formula (a1),
R ^{a1 to} R ^a6 are independently hydrogen atoms, halogen atoms, alkyl groups having 1 to 4 carbon atoms, or alkoxy groups having 1 to 4 carbon atoms, and R ^a1 and R ^a5 are They may be bonded to each other to form -O-, -S-, -CH _2- , or -CR ^a7 R ^a8- , and Ra ³ and Ra ⁴ may be bonded to each other to form 6 or more and 12 or less carbon atoms. It may form a ring,
R ^a7 and R ^a8 are independently hydrogen atoms, alkyl groups having 1 or more and 4 or less carbon atoms, or alkoxy groups having 1 or more and 4 or less carbon atoms. )
By condensing with the dicarboxylic acid anhydride represented by, the following formula (a3):

(In the formula ^{(a3), R a01} and ^{R a02} are the same as ^{R a01} and ^{R a02} in the formula ^{(a1), R} a1 ~R ^a6, like the ^R a1 ^{to R a6} in the formula (a2) Is.)
The first step of producing the group indicated by
The second step is to heat the intermediate compound having the group represented by the formula (a3) produced in the first step to convert the group represented by the formula (a3) into the group represented by the formula (a1). It can be manufactured by a manufacturing method including a process.

^{Specific examples of the halogen atom as R a1 to} R ^a6 in the formula (a2) include a chlorine atom, a fluorine atom, a bromine atom, and an iodine atom.
^{The alkyl group having 1 or more and 4 or less carbon atoms as R a1 to} R ^a6 in the formula (a2) may be linear or branched, and specific examples thereof include a methyl group, an ethyl group, and an n-propyl group. , N-Butyl group, isopropyl group, isobutyl group, sec-butyl group, tert-butyl group.
^{The alkoxy group having 1 to 4 carbon atoms as R a1 to} R ^a6 in the formula (a2) may be a straight chain or a branched chain, and specific examples thereof include a methoxy group, an ethoxy group, and an n-propoxy group. Examples thereof include an isopropoxy group and an n-butoxy group.
The alkyl groups having 1 to 4 carbon atoms and the alkoxy groups having 1 to 4 carbon atoms as R ^a7 and R ^a8 are the alkyl groups having 1 to 4 carbon atoms and 1 carbon atoms as ^{R a1 to} R ^a6. It is the same as the above 4 or less alkoxy groups.

In the first step, the primary amino group in the raw material compound having a primary amino group is condensed with the dicarboxylic acid anhydride represented by the above formula (a2), and the group represented by the above formula (a3) is condensed. To generate. As a result, a resin having a group represented by the formula (a3) can be obtained.

Examples of the raw material compound having a primary amino group include a polymer of a monomer having an unsaturated double bond. Examples of such a resin include a (meth) acrylic resin having a primary amino group and a polystyrene resin having a primary amino group. More specific examples include a (meth) acrylic resin having a primary amino group at the end of the side chain and a polystyrene resin having a primary amino group at the end of the side chain.
The "(meth) acrylic resin having a primary amino group" is a (meth) acrylic resin containing a structural unit having a primary amino group. The structural unit having a primary amino group may be a structural unit derived from a (meth) acrylic acid ester or a structural unit derived from an N-substituted (meth) acrylamide, and these constituent units may be used. It may be a structural unit other than the unit. The structural unit having a primary amino group is preferably a structural unit derived from a (meth) acrylic acid ester and / or a structural unit derived from an N-substituted (meth) acrylamide.
The "polystyrene resin having a primary amino group" is a polystyrene resin containing a structural unit having a primary amino group. The structural unit having a primary amino group may be a structural unit derived from aminostyrene such as p-aminostyrene, m-aminostyrene, and o-aminostyrene, and may be a structural unit derived from aminostyrene such as p-aminomethylstyrene and m-amino. It may be a structural unit derived from a styrene derivative having an amino group such as methyl styrene and o-aminomethyl styrene, or may be a structural unit other than these structural units. The structural unit having a primary amino group is preferably a structural unit derived from aminostyrene and / or a structural unit derived from a styrene derivative having an amino group.
A resin having a primary amino group, such as a (meth) acrylic resin having a primary amino group or a polystyrene resin having a primary amino group, preferably has a primary amino group at the end of the side chain. ..
In a (meth) acrylic resin having a primary amino group at the end of the side chain or a polystyrene resin having a primary amino group at the end of the side chain, the primary amino group is bonded when the side chain is a branched chain. The end of the side chain may be any end of the two or more branched chains of the branched chain. When the structure at the end of the side chain is a ring structure, any position of the ring constituting the ring structure is the end of the side chain to which the primary amino group is bonded.
For example, when the side chain consists of an α-naphthyl group or a β-naphthyl group, an arbitrary position on the naphthalene ring is the end of the side chain. When the group constituting the side chain is a branched 1-phenylethyl group, the methyl group corresponding to the end of the two branch chains and an arbitrary position on the phenyl group are at the end of the side chain. is there.

In the method for producing a maleimide-modified resin (A1), the resin having a primary amino group (raw material compound) is produced by homopolymerizing a monomer having a primary amino group to produce a raw material compound which is a resin, or , It is preferable to include copolymerizing a monomer having a primary amino group and a comonomer to produce a raw material compound which is a resin.
Examples of the monomer having a primary amino group include aminomethyl (meth) acrylate, 2-aminoethyl (meth) acrylate, 3-aminopropyl (meth) acrylate, 4-aminophenyl (meth) acrylate, and 3-aminophenyl (3-aminophenyl). (Meta) acrylates such as meta) acrylate, 2-aminophenyl (meth) acrylate, 4-aminophenylmethyl (meth) acrylate, 3-aminophenylmethyl (meth) acrylate, and 2-aminophenylmethyl (meth) acrylate N-2-aminoethyl (meth) acrylamide, N-3-aminopropyl (meth) acrylamide, N-4-aminophenyl (meth) acrylamide, N-3-aminophenyl (meth) acrylamide, and N-2- (Meta) acrylamides such as aminophenyl (meth) acrylamide; aminostyrenes such as p-aminostyrene, m-aminostyrene, and o-aminostyrene; p-aminomethylstyrene, m-aminomethylstyrene, and o-amino Examples thereof include aminoalkylstyrene such as methylstyrene.

The comonomer is a monomer other than the monomer having a primary amino group. Examples of the comonomer include compounds represented by the following formula (a-I).
CH ₂ = CR ^a11- CO- ^{OR a10} ... (a-I)
In formula (a-I), R ^a10 is a monovalent organic group and R ^a11 is a hydrogen atom or a methyl group. This organic group may contain a bond or a substituent other than the hydrocarbon group such as a hetero atom in the organic group. Further, the organic group may be linear, branched or cyclic.

The substituent other than a hydrocarbon group in the organic group R ^a10, the effect is not particularly limited as long as they do not impair the present invention, a halogen atom, a hydroxyl group, a mercapto group, a sulfide group, a cyano group, an isocyano group, a cyanato group , Isocyanato group, thiocyanato group, isothiocyanato group, silyl group, silanol group, alkoxy group, alkoxycarbonyl group, carbamoyl group, thiocarbamoyl group, nitro group, nitroso group, carboxy group, carboxylate group, acyl group, acyloxy group, sulfino Group, sulfo group, sulfonate group, phosphino group, phosphinyl group, phosphono group, phosphonato group, hydroxyimino group, alkyl ether group, alkyl thioether group, aryl ether group, aryl thioether group, N-mono-substituted amino group, and N, Examples thereof include an N-di-substituted amino group. The hydrogen atom contained in the above substituent may be substituted with a hydrocarbon group. The hydrocarbon group contained in the substituent may be linear, branched or cyclic.

As R ^a10 , an alkyl group, an aryl group, an aralkyl group, or a heterocyclic group is preferable. These groups may be substituted with halogen atoms, hydroxyl groups, alkyl groups, or heterocyclic groups. When these groups contain an alkylene moiety, the alkylene moiety may be interrupted by an ether bond, a thioether bond, or an ester bond.

When the alkyl group is linear or branched, the number of carbon atoms thereof is preferably 1 or more and 20 or less, more preferably 1 or more and 15 or less, and particularly preferably 1 or more and 10 or less. Examples of suitable alkyl groups include methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, sec. -Pentyl group, tert-pentyl group, n-hexyl group, n-heptyl group, n-octyl group, isooctyl group, sec-octyl group, tert-octyl group, n-nonyl group, isononyl group, n-decyl group, Examples thereof include an isodecyl group.

When the alkyl group is an alicyclic group or a group containing an alicyclic group, suitable alicyclic groups contained in the alkyl group include a cyclopentyl group, a monocyclic alicyclic group such as a cyclohexyl group, and the like. , Adamantyl group, norbornyl group, isobornyl group, tricyclononyl group, tricyclodecyl group, tetracyclododecyl group and other polycyclic alicyclic groups.

Other preferred examples of comonomer include (meth) acrylamides, unsaturated carboxylic acids, allyl compounds, vinyl ethers, vinyl esters, styrenes and the like. These comonomer can be used alone or in combination of two or more.

Examples of (meth) acrylamides include (meth) acrylamide; N-methyl (meth) acrylamide, N-ethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, and N-isopropyl (meth) acrylamide. N-alkyl (meth) acrylamide such as n-butyl (meth) acrylamide; N-aryl such as N-phenyl (meth) acrylamide, N-α-naphthyl (meth) acrylamide, and N-β-naphthyl (meth) acrylamide. (Meta) acrylamide; N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide, N, N-di-n-propyl (meth) acrylamide, and N, N-di-n-butyl ( N, N-dialkyl (meth) acrylamide such as meta) acrylamide; N, N-diaryl (meth) acrylamide such as N, N-diphenyl (meth) acrylamide; N-methyl-N-phenyl (meth) acrylamide, and N Other N, N di-substituted (meth) acrylamides such as -hydroxyethyl-N-methyl (meth) acrylamide can be mentioned.

Examples of unsaturated carboxylic acids include monocarboxylic acids such as crotonic acid; dicarboxylic acids such as maleic acid, fumaric acid, citraconic acid, mesaconic acid, and itaconic acid; and anhydrides of these dicarboxylic acids.

Examples of the allyl compound include allyl esters such as allyl acetate, allyl caproate, allyl caprylate, allyl laurate, allyl palmitate, allyl stearate, allyl benzoate, allyl acetoacetate, and allyl lactate; allyloxyethanol; and the like. Can be mentioned.

Examples of vinyl ethers include hexyl vinyl ether, octyl vinyl ether, decyl vinyl ether, ethyl hexyl vinyl ether, methoxyethyl vinyl ether, ethoxyethyl vinyl ether, chloroethyl vinyl ether, 1-methyl-2,2-dimethylpropyl vinyl ether, 2-ethylbutyl vinyl ether and hydroxyethyl vinyl ether. , Diethylene glycol vinyl ether, dimethylaminoethyl vinyl ether, diethylaminoethyl vinyl ether, butylaminoethyl vinyl ether, benzyl vinyl ether, tetrahydrofurfuryl vinyl ether and other alkyl vinyl ethers; vinyl phenyl ether, vinyl trill ether, vinyl chlorophenyl ether, vinyl-2,4-dichlorophenyl ether. , Vinyl aryl ethers such as vinyl naphthyl ethers and vinyl anthranyl ethers; and the like.

Examples of vinyl esters include vinyl butyrate, vinyl isobutyrate, vinyl trimethyl acetate, vinyl diethyl acetate, vinyl ballerate, vinyl caproate, vinyl chloro acetate, vinyl dichloro acetate, vinyl methoxy acetate, vinyl butoxy acetate, and vinyl phenyl. Examples thereof include acetate, vinyl acetoacetate, vinyl lactate, vinyl-β-phenylbutyrate, vinyl benzoate, vinyl salicylate, vinyl chlorobenzoate, vinyl tetrachlorobenzoate, vinyl naphthoate and the like.

Styrenes include styrene; methylstyrene, dimethylstyrene, trimethylstyrene, ethylstyrene, diethylstyrene, isopropylstyrene, butylstyrene, hexylstyrene, cyclohexylstyrene, decylstyrene, benzylstyrene, chloromethylstyrene, trifluoromethylstyrene, ethoxy. Alkylstyrene such as methylstyrene and acetoxymethylstyrene; alkoxystyrene such as methoxystyrene, 4-methoxy-3-methylstyrene and dimethoxystyrene; chlorostyrene, dichlorostyrene, trichlorostyrene, tetrachlorostyrene, pentachlorostyrene, bromostyrene, Examples thereof include halostyrene such as dibromostyrene, iodostyrene, fluorostyrene, trifluorostyrene, 2-bromo-4-trifluoromethylstyrene, and 4-fluoro-3-trifluoromethylstyrene.

The ratio of the monomer having a primary amino group to the monomer having a primary amino group and the comonomer in the case of copolymerizing the comonomer is not particularly limited, but for example, it has a primary amino group on a molar basis. Monomer: copolymer = 5-50: 50-95.

（式（ａ２−１）中、Ｒ^ａ０１、Ｒ^ａ０２、Ｒ^ａ２、Ｒ^ａ３、Ｒ^ａ４及びＲ^ａ６は、式（ａ２）中のＲ^ａ０１、Ｒ^ａ０２、Ｒ^ａ２、Ｒ^ａ３、Ｒ^ａ４及びＲ^ａ６と同様である。）
で表される化合物が挙げられる。 Examples of the compound represented by the formula (a2) include the following formula (a2-1):

(In the formula ^{(a2-1), R a01, R} a02, R a2, R a3, R a4 and ^{R a6} is, ^R a01 in the formula ^{(a2), R a02, R} a2, R a3, R a4 and R ^Same as a6.)
Examples thereof include compounds represented by.

The compound represented by the formula (a2) can be obtained, for example, by a Diels-Alder reaction between a compound represented by the following formula and a conjugated diene compound corresponding to the structure of the compound represented by the formula (a2).
The conditions for this Diels-Alder reaction may be appropriately set according to the type of raw material used, or the reaction may be carried out in an organic solvent.

Examples of the organic solvent used in the deal alder reaction include esters such as ethyl acetate, butyl acetate and cellosolve acetate; ketones such as acetone, methyl ethyl ketone, isobutyl ketone and methyl isobutyl ketone; ethyl acetate, butyl acetate and malonic acid. Esters such as diethyl; amides such as N-methylpyrrolidone, N, N-dimethylformamide; ethers such as diethyl ether, ethylcyclopentyl ether, tetrahydrofuran, dioxane; aromatic hydrocarbons such as toluene and xylene; hexane, Aliphatic hydrocarbons such as heptane, octane and decahydronaphthalene, halogenated hydrocarbons such as methylene chloride and ethylene chloride; dimethyl sulfoxide, dimethyl sulfoamide and the like can be mentioned. As the organic solvent to be used, one kind of solvent may be used, or two or more kinds may be used in any combination.
The reaction temperature that can be adopted is, for example, in the range of −10 ° C. to 200 ° C., preferably in the range of 0 ° C. to 150 ° C., and more preferably in the range of 5 ° C. to 120 ° C.
The reaction time that can be adopted is, for example, 5 minutes or more and 12 hours or less, 10 minutes or more and 10 hours or less, and 30 minutes or more and 8 hours or less.

Condensation in the first step is usually carried out using a condensing agent. Examples of the dehydration condensing agent include carbonyldiimidazole, carbodiimide-based compounds and the like.
The addition of this condensing agent may be carried out in the reaction vessel in which the Diels-Alder reaction described above has been carried out, or the product in the Diels-Alder reaction may be separately isolated and then dissolved again in an organic solvent or the like and added. May be done.
As the organic solvent used in this condensation, the same organic solvent as that used in the Diels-Alder reaction can be adopted.
The reaction temperature that can be adopted is, for example, in the range of −10 ° C. to 200 ° C., preferably in the range of 0 ° C. to 150 ° C., and more preferably in the range of 5 ° C. to 120 ° C.
The reaction time that can be adopted is, for example, 5 minutes or more and 12 hours or less, 10 minutes or more and 10 hours or less, and 30 minutes or more and 8 hours or less.

The compound having a group represented by the above formula (a3) obtained by carrying out the first step may be isolated after carrying out the first step.
When the compound having a group represented by the above formula (a3) is a resin, this isolation is performed by, for example, solidifying the reaction solution after the condensation in the first step is completed by pouring it into a poor solvent, and filtering this. It is done by taking.

In the second step, the compound having the group represented by the above formula (a3) produced in the first step is heated, and the group represented by the above formula (a3) is represented by the above formula (a1). Convert to a group (reverse Diels-Alder reaction). As a result, the maleimide-modified compound (A) having a group represented by the above formula (a1) is obtained.
The groups represented by the above formula (a1) may be all or part of the amino groups derived from the monomer having a primary amino group which is a raw material compound, depending on the amount of the compound represented by the formula (a2) used. Can be introduced.

The reverse Diels-Alder reaction in the second step is carried out, for example, in an organic solvent. The organic solvent used can be the same as the organic solvent used in the Diels-Alder reaction described above, but the boiling point is preferably 60 ° C. or higher, and the boiling point is 80 ° C. or higher in order to carry out the reaction by heating. It is more preferable that the boiling point is 100 or more. The upper limit of the boiling point is not particularly limited, but is, for example, 350 ° C. or lower.
Regarding the heating in the second step, the reaction temperature that can be adopted is, for example, in the range of 60 ° C. to 280 ° C., preferably in the range of 80 ° C. to 250 ° C., and more preferably in the range of 100 ° C. to 225 ° C.
The reaction time that can be adopted is, for example, 5 minutes or more and 12 hours or less, preferably 10 minutes or more and 10 hours or less, and more preferably 30 minutes or more and 8 hours or less.

Further, the compound having a group represented by the above formula (a1) obtained by carrying out the second step may be isolated after carrying out the second step.
When the compound having a group represented by the above formula (a1) is a resin, this isolation is carried out, for example, by pouring the reaction solution after the condensation in the second step into a poor solvent (for example, an alcohol solvent) to solidify it. It is done by making it into a solvent and collecting it.

As an example of the method for producing the maleimide-modified compound (A), a copolymer of aminostyrene, which is a monomer having a primary amino group, and styrene, which is a comonomer, was used as a raw material compound having a primary amino group. The reaction formula of the case is shown below. In the following reaction formula, the second step shows an example of reflux in toluene. Further, m and n in the following reaction formulas are the number of repetitions of the constituent units, respectively.

According to the method for producing the maleimide-modified compound (A), side reactions other than maleimide formation are suppressed. In particular, when the maleimide-modified resin (A1) is produced, according to the above method, as a result of suppressing side reactions, the maleimide-modified resin (A1) having a group represented by the formula (a1) can be obtained in a solid state. Can be done. Therefore, for example, a maleimide-modified resin (A1) having a group represented by the formula (a1) can be blended with the curable composition as a solid resin. For example, a polymer of a monomer having an unsaturated double bond containing a group represented by the above formula (a1) at the end of a side chain has a problem of gelation, and thus is conventionally obtained as a solid resin. I couldn't. Specifically, for example, in the method of ring-closing a styrene resin having an amino group by reacting maleic anhydride with the styrene resin, gelation occurred and a solid resin could not be obtained. It is considered that this is because side reactions other than the desired maleimideization are likely to occur. However, according to the above-mentioned production method, a polymer of a monomer having an unsaturated double bond containing a group represented by the formula (a1) can be obtained as a solid resin.
In the specification of the present application, the substituted or unsubstituted cyclic imide group represented by the formula (a1) is also referred to as a "maleimide group" for convenience.

Further, according to the above-mentioned production method, instead of polymerizing a monomer having a maleimide group introduced therein, a prepolymerized polymer is used as a raw material compound, and the primary amino group of the polymer is reacted to carry out the formula (a1). Polymerization is not limited to time-consuming cationic polymerization due to the introduction of the represented groups. Therefore, the above manufacturing method is a simple method.

Further, a primary amino group and a dicarboxylic acid anhydride represented by the formula (a2) are condensed to form a group represented by the formula (a3), and then heated to be represented by the formula (a3). Since the group is converted to the group represented by the formula (a1), the group represented by the formula (a1) can be reliably introduced without causing a problem due to the ring closure reaction.

<Maleimide-modified polyphenylene ether resin (A1-1)>
As described above, the maleimide-modified compound (A) has been mainly described as the maleimide-modified resin (A1), but the maleimide-modified polyphenylene ether resin (A1-1) having a group represented by the formula (a1) is also a maleimide-modified resin (A1). ) Is preferable. The maleimide-modified polyphenylene ether resin (A1-1) is preferably a resin in which the molecular chain end of the unmodified polyphenylene ether resin is modified by a terminal group containing a group represented by the formula (a1). The structure of the terminal group including the group represented by the formula (a1) is not particularly limited as long as the object of the present invention is not impaired.
The phenylene group contained in the main chain of the maleimide-modified polyphenylene ether resin (A1-1) may have a substituent of 1 or more and 4 or less.
When the maleimide-modified polyphenylene ether resin (A1-1) has a terminal group containing a group represented by the formula (a1), the terminal group has the following formula (Ai):
* -Y ^2- Y ¹ -** ... (Ai)
It is preferable to bond to the main chain of the maleimide-modified polyphenylene ether resin (A1-1) via the linking group represented by.
The **-side bond in the linking group binds to an oxygen atom derived from the hydroxyl group at the end of the molecular chain of the unmodified polyphenylene ether resin that gives the maleimide-modified polyphenylene ether resin (A1-1). On the other hand, the * -side bond in the linking group binds to the terminal group.
In formula (Ai), Y ¹ is a single bond or a carbonyl group. Y ² is a divalent organic group. If Y ¹ is a single bond, a single bond as Y ¹ is bonded to the carbon atoms taking sp3 hybrid orbital in the divalent organic group as Y ^2.

In the formula (Ai), when Y ¹ is a carbonyl group, it is preferable that Y ² is a group represented by ^{−Y 4−} Y ^3−. Y ³ represents a single bond, -O-, or -NH-. Y ⁴ is a divalent organic group. Y ³ binds to the carbonyl group as Y ^{1.
That is, when Y 1} in the formula (Ai) is a carbonyl group, the linking group represented by the formula (Ai) is a group represented by the following formulas (Ai-1) to (Ai-3). Is preferable.
* -Y ^4- CO-** ... (Ai-1)
* -Y ^4- O-CO-** ... (Ai-2)
* -Y ^4- NH-CO-** ... (Ai-3)

The divalent organic group as ^{Y 4} is not particularly limited as long as it is a group capable of linking ^{Y 3 and the terminal group represented by the formula (a1).} The structure of the organic group may be linear, branched, cyclic, or a combination of these structures. Examples of heteroatoms other than carbon atoms and hydrogen atoms that can be contained in organic groups include nitrogen atoms, sulfur atoms, oxygen atoms, halogen atoms, phosphorus atoms, silicon atoms, and boron atoms. The organic group may have one or more unsaturated bonds.
The Y ^4, or a easily available or the preparation of the compounds used in the end degeneration in maleimide-modified polyphenylene ether resin (A1-1), the like it or an easy desired end modification, hydrocarbon groups are preferred ..
The number of carbon atoms of the hydrocarbon group is preferably 1 or more and 10 or less, more preferably 1 or more and 8 or less, and further preferably 1 or more and 6 or less.
The hydrocarbon group may be an aliphatic hydrocarbon group or an aromatic hydrocarbon group. As the hydrocarbon group, a aliphatic hydrocarbon group is preferable because it is more flexible than a rigid aromatic hydrocarbon group.

The preferred hydrocarbon groups as Y ^4, a methylene group, ethane-1,2-diyl, ethane-1,1-diyl group, propane-1,3-diyl, propane-1,2-diyl group, propane -1,1-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1,7-diyl group, octane-1,8- Diyl group, nonan-1,9-diyl group, decan-1,10-diyl group, cyclohexane-1,4-diyl group, cyclohexane-1,3-diyl group, cyclohexane-1,2-diyl group, p-phenylene Examples thereof include a group, an m-phenylene group, an o-phenylene group, a naphthalene-1,4-diyl group, a naphthalene-2,6-diyl group, and a naphthalene-2,7-diyl group.
Among these, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, cyclohexane-1,4-diyl group, and cyclohexane-1,3-diyl group Is preferable.

In the formula (Ai), when Y ¹ is a single bond, a single bond as Y ¹ is bonded to the carbon atoms taking sp3 hybrid orbital in the divalent organic group as Y ^2. carbon atoms taking sp3 hybrid orbital is typically in the organic group as Y ^2, is a carbon atom constituting the entire structure or a partial structure consisting of an aliphatic hydrocarbon group.

In formula (Ai), when Y ¹ is a single bond, the ^{divalent organic group as Y 2} has at least one carbon atom in the sp3 hybrid orbital and is a terminal maleimide-modified polyphenylene ether resin (A1-). The group is not particularly limited as long as it is a group capable of linking an oxygen atom derived from a hydroxyl group at the terminal of the molecular chain of the unmodified polyphenylene ether resin that gives 1) to the terminal group represented by the formula (a1). When Y ¹ is a single bond, the ^{divalent organic group as Y 2} is a nitrogen atom, a sulfur atom, an oxygen atom, a halogen atom, a phosphorus atom, a silicon atom, and a boron atom in addition to the carbon atom and the hydrogen atom. It may contain one or more heteroatoms such as.

When Y ¹ is a single bond, the ^{number of carbon atoms of the divalent organic group as Y 2} is preferably 1 or more and 10 or less, more preferably 1 or more and 8 or less, and further preferably 1 or more and 6 or less.

When Y ¹ is a single bond, the ^{divalent organic group as Y 2} has one or more methylene groups as a carbonyl group (-CO-), an ether bond (-O-), or an imino group (-NH-). It is preferably an aliphatic hydrocarbon group that may be substituted with).
When Y ¹ is a single bond, the ^{preferred aliphatic hydrocarbon group as Y 2} is a methylene group, an ethane-1,2-diyl group, an ethane-1,1-diyl group, a propane-1,3-diyl group. , Propane-1,2-diyl group, propane-1,1-diyl group, butane-1,4-diyl group, pentane-1,5-diyl group, hexane-1,6-diyl group, heptane-1, 7-Diyl Group, Octane-1,8-Diyl Group, Nonan-1,9-Diyl Group, Decane-1,10-Diyl Group, Cyclohexane-1,4-Diyl Group, Cyclohexane-1,3-Diyl Group, and Cyclohexane-1,2-diyl groups can be mentioned. Further, a group in which one or two methylene groups contained in these hydrocarbon groups are substituted with a carbonyl group (-CO-), an ether bond (-O-), or an imino group (-NH-) is also preferable.
Among these, ethane-1,2-diyl group, propane-1,3-diyl group, butane-1,4-diyl group, cyclohexane-1,4-diyl group, and cyclohexane-1,3-diyl group Is preferable.

The method of introducing a terminal group represented by the formula (a1) into the molecular chain terminal of the unmodified polyphenylene ether resin for modification is not particularly limited.
In order to carry out such modification, an unmodified polyphenylene ether resin having a phenolic hydroxyl group terminal is preferably used.

The unmodified polyphenylene ether resin may be a resin having at least one phenolic hydroxyl group terminal. The unmodified polyphenylene ether resin preferably has two or more phenolic hydroxyl group ends, more preferably has two or three phenolic hydroxyl group ends, and even more preferably has two phenolic hydroxyl group ends.
When the unmodified polyphenylene ether resin has a phenolic hydroxyl group at the terminal, the unmodified polyphenylene ether resin may further have a phenolic hydroxyl group on the phenylene group contained in the main chain.

Polyphenylene ether resins can typically be produced by oxidatively polymerizing a phenolic compound such as 2,6-dimethylphenol in the presence of a catalyst containing a metal such as copper. The method for producing the unmodified polyphenylene ether resin is not particularly limited, but it is preferable that the unmodified polyphenylene ether resin is produced according to the above-mentioned typical method according to a known method.

The phenylene group contained in the main chain of the maleimide-modified polyphenylene ether resin (A1-1) may have a substituent of 1 or more and 4 or less. Therefore, the phenylene group contained in the sponsorship of the unmodified polyphenylene ether resin may also have a substituent of 1 or more and 4 or less.
Examples of substituents are alkyl groups having 1 to 4 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, and tert-butyl group. Aromatic hydrocarbon groups such as groups, phenyl groups, o-tolyl groups, m-tolyl groups, and p-tolyl groups, methoxy groups, ethoxy groups, n-propyloxy groups, isopropyloxy groups, n-butyloxy groups, isobutyls. An alkoxy group having 1 to 4 carbon atoms such as an oxy group, a sec-butyloxy group, and a tert-butyloxy group, and a halogen atom such as a phenolic hydroxyl group, a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom are preferable.
Among these substituents, a methyl group, a phenyl group, a chlorine atom and a bromine atom are preferable, and a methyl group, a phenyl group and a chlorine atom are more preferable.

Examples of the unmodified polyphenylene ether resin include homopolymers of phenols and copolymers of two or more kinds of phenols.
The unmodified polyphenylene ether resin may be a polymer obtained by polymerizing only monovalent phenol, or a polymer obtained by copolymerizing monohydric phenol with polyhydric phenol such as dihydric phenol or trihydric phenol. There may be.
A polymer containing only monohydric phenol has an aryl group derived from a raw material phenol having no hydroxyl group at one end and a hydroxyaryl group derived from the raw material phenol at the other end.

In the copolymer of monohydric phenol and polyhydric phenol, the molecular chain of polyphenylene ether grows starting from two or more phenolic hydroxyl groups of the polyhydric phenol. Therefore, when a monohydric phenol is copolymerized with a divalent phenol, a polyphenylene ether resin having a hydroxyaryl group at both ends can be obtained. Further, when a monohydric phenol is copolymerized with a phenol having a valence of 3 or more, a polyphenylene ether resin having a branched chain corresponding to the valence of the polyvalent phenol and having a hydroxyaryl group at the end of each branched chain can be obtained.

Specific examples of the homopolymers of phenols include poly (2,6-dimethyl-1,4-phenylene ether), poly (2-methyl-6-phenyl-1,4-phenylene ether), and poly (2, 6-Dichloro-1,4-phenylene ether) and the like.
As described above, the copolymer of two or more kinds of phenols may be a copolymer of two or more kinds of monovalent phenols, and one or more kinds of monovalent phenols and one or more kinds of divalent phenols. It may be a copolymer of.
Specific examples of copolymers of two or more monohydric phenols include copolymers of 2,6-dimethylphenol and 2,3,6-trimethylphenol, and 2,6-dimethylphenol and 2,6-trimethylphenol. Examples thereof include a copolymer with dichlorophenol and a copolymer of 2,6-dimethylphenol and 2-methyl-6-phenylphenol.
As a copolymer of one or more monovalent phenols and one or more divalent phenols, 3,3', 5,5'-tetramethylbisphenol A is polymerized with 2,6-dimethylphenol. A polymer, a copolymer obtained by polymerizing 2-methyl-6-phenylphenol on 3,3', 5,5'-tetramethylbisphenol A, or 3,3', 5,5'-tetramethylbisphenol A. Examples thereof include a copolymer obtained by polymerizing 2,6-dichlorophenol.

As the unmodified polyphenylene ether resin, 2,6-dimethylphenol is polymerized with 3,3', 5,5'-tetramethylbisphenol A, which is a copolymer of monohydric phenol and divalent phenol. Polymers, copolymers obtained by polymerizing 2-methyl-6-phenylphenol on 3,3', 5,5'-tetramethylbisphenol A, and 3,3', 5,5'-tetramethylbisphenol A A copolymer obtained by polymerizing 2,6-dichlorophenol is preferable, and a copolymer obtained by polymerizing 2,6-dimethylphenol A with 3,3', 5,5'-tetramethylbisphenol A is more preferable.

The method of modifying the unmodified polyphenylene ether resin to introduce the terminal group represented by the formula (a1) into the terminal is not particularly limited.
For example, in the formula (Ai), Y ¹ is a carbonyl group, and the linking group represented by the formula (Ai) is the following formula (Ai-1) :.
* -Y ^4- CO-** ... (Ai-1)
In the case of a group represented by MIG-Y ^4- CO-OH, the carboxylic acid represented by MIG-Y 4-CO-OH and the phenolic hydroxyl group of the unmodified polyphenylene ether resin are combined with carbonyldiimidazole or N, N'-diisopropylcarbodiimide. By condensing with a condensing agent such as a carbodiimide-based compound such as, the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin can be converted into a group represented by ^{-O-CO-Y 4-MIG.} .. MIG is a terminal group represented by the formula (a1).
Further, by reacting the carboxylic acid halide represented by MIG-Y ^4- CO-Hal with the phenolic hydroxyl group of the unmodified polyphenylene ether resin, the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin can be obtained by-. It can be converted to a group represented by O-CO-Y ^4-MIG. Hal is a halogen atom such as a chlorine atom and a bromine atom.

In the formula (Ai), Y ¹ is a carbonyl group, and the linking group represented by the formula (Ai) is the following formula (Ai-2):
* -Y ^4- O-CO-** ... (Ai-2)
In the case of a group represented by, the phenolic hydroxyl group of the unmodified polyphenylene ether resin and the ^{alcohol represented by MIG-Y 4-} OH in an excess amount with respect to the phenolic hydroxyl group are mixed with carbonates such as phosgen and triphosgen. By reacting with a compound that forms a bond, the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin can be converted into a group represented by ^{-O-CO-O-Y 4-MIG.}

In the formula (Ai), Y ¹ is a carbonyl group, and the linking group represented by the formula (Ai) is the following formula (Ai-3):
* -Y ^4- NH-CO-** ... (Ai-3)
In the case of a group represented by, the phenolic hydroxyl group ^{of the unmodified polyphenylene ether resin is reacted with the isocyanate represented by MIG-Y 4-} NCO to obtain the terminal phenolic hydroxyl group of the unmodified polyphenylene ether resin. , -O-CO-NH-Y ^4- MIG can be converted to a group.

^{When Y 1} is a single bond in the formula (Ai), the phenolic hydroxyl group of the unmodified polyphenylene ether resin and the ^{halide represented by MIG-Y 2-} Hal are combined by a method such as so-called Williamson ether synthesis. by etherification can be converted to terminal phenolic hydroxyl groups of an unmodified polyphenylene ether resin, a group represented by -O-Y ² -MIG.

The typical method for modifying a phenolic hydroxyl group has been described above, but the method for modifying a phenolic hydroxyl group is not limited to these methods, and depends on the structure of the linking group bonded to the terminal group represented by the formula (a1). Therefore, various known methods can be adopted.
Further, in the above-mentioned modification method, if necessary, an organic solvent according to the adopted reaction can be appropriately used. As for the reaction temperature and reaction time, known suitable conditions in the adopted reaction can be appropriately adopted.

When the maleimide-modified polyphenylene ether resin (A1-1) is prepared using the unmodified polyphenylene ether resin, a terminal group represented by the formula (a1) is added to a part of the phenolic hydroxyl groups of the unmodified polyphenylene ether resin. A group containing a terminal group may be introduced, or a group containing a terminal group represented by the formula (a1) may be introduced into all of the phenolic hydroxyl groups.

The molecular weight of the maleimide-modified polyphenylene ether resin (A1-1) is not particularly limited as long as the effect of the present invention is not impaired, but the mass average molecular weight (Mw) is preferably 2000 or more, and more preferably 2500 or more. It is preferably 3000 or more, and more preferably 3000 or more. The molecular weight of the maleimide-modified polyphenylentel resin (A1-1) is preferably 100,000 or less, more preferably 80,000 or less, further preferably 50,000 or less, still more preferably 10,000 or less, as the mass average molecular weight (Mw). ..

The maleimide-modified resin (A1) having a group represented by the formula (a1) has been described above, but the group represented by the formula (a1), which is a maleimide-modified compound (A) other than the maleimide-modified resin (A1). Examples of the maleimide-modified monomer (A2) having the above include a bismaleimide compound in which two amino groups of an aromatic diamine and an aliphatic diamine are replaced with a group represented by the formula (a1).

Specific examples of aromatic diamines include p-phenylenediamine, m-phenylenediamine, 2,4-diaminotoluene, 4,4'-diaminobiphenyl, and 4,4'-diamino-2,2'-bis (trifluoro). Methyl) biphenyl, 3,3'-diaminodiphenyl sulphon, 4,4'-diaminodiphenyl sulphon, 4,4'-diaminodiphenyl sulfide, 4,4'-diaminodiphenyl methane, 4,4'-diaminodiphenyl ether, 3,4 '-Diaminodiphenyl ether, 3,3'-diaminodiphenyl ether, 1,4-bis (4-aminophenoxy) benzene, 1,3-bis (4-aminophenoxy) benzene, 1,3-bis (3-aminophenoxy) Benzene, 4,4'-bis (4-aminophenoxy) biphenyl, bis [4- (4-aminophenoxy) phenyl] sulphon, bis [4- (3-aminophenoxy) phenyl] sulphon, 2,2-bis [ Examples thereof include 4- (4-aminophenoxy) phenyl] propane and 2,2-bis [4- (4-aminophenoxy) phenyl] hexafluoropropane.
Specific examples of the aliphatic diamine include pentamethylenediamine, hexamethylenediamine, heptamethylenediamine, 2,3,3-trimethylpentane-1,5-diamine and the like.
Commercially available and highly available maleimide-modified monomers (A2) include 2,2-bis [4- (4-maleimidephenoxy) phenyl] propane, the following compounds (all manufactured by Tokyo Chemical Industry Co., Ltd.), and BMI. -689, BMI-1400, BMI-1500, BMI-1700, BMI-2700, BMI-3000 (all manufactured by Designer malecules) can also be mentioned.

As described above, the maleimide-modified compound (A) having a terminal group represented by the formula (a1) at the end of the molecular chain is exposed or heated because the terminal group represented by the formula (a1) is a radically polymerizable group. Can be polymerized. As a result of the polymerization, the maleimide-modified compound (A) provides an insulating film having a low dielectric constant, a low dielectric loss tangent, and excellent heat resistance. For example, the dielectric constant of the formed insulating film can be less than 3.00. Further, the dielectric loss tangent of the formed insulating film can be less than 0.01. Further, the glass transition temperature (Tg) of the formed insulating film can be set to 150 ° C. or higher.
Further, the curable composition containing the maleimide-modified compound (A) is excellent in film-forming property by the coating method, that is, when the film is formed by the coating method, cracks and crystals do not occur and tack (stickiness) is obtained. ), And the compatibility of the components is good. Therefore, the insulating film can be formed by a coating method, which is an easy method.

The maleimide-modified compound (A) is excellent in solvent solubility. Therefore, the curable composition containing the maleimide-modified compound (A) can be applied as a negative type composition to the developing process using the solvent.
In particular, the maleimide-modified compound (A) may be soluble in an alkaline aqueous solution, depending on its structure. For example, the maleimide-modified compound (A) has an alkali-soluble group such as a carboxy group or a phenolic hydroxyl group. The curable composition containing such an alkali-soluble maleimide-modified compound (A) can be applied to an alkali development process as a negative composition.
By applying regioselective exposure and the above-mentioned developing process to a coating film made of a curable composition containing a maleimide-modified compound (A), a cured film having a desired pattern shape can be formed. it can.

The content of the maleimide-modified compound (A) in the curable composition is not particularly limited. The content of the maleimide-modified compound (A) is preferably 5% by mass or more and 100% by mass or less with respect to the total solid content of the curable composition.
When the curable composition contains the maleimide-modified resin (A1) and the maleimide-modified monomer (A2) as the maleimide-modified compound (A), the mass W1 of the maleimide-modified resin (A1) and the maleimide-modified monomer (A2) The ratio W1: W2 to the mass W2 is preferably 10:90 to 90:10, more preferably 20:80 to 80:20. The ratio W1: W2 may be 30:70 to 70:30 and may be 40:60 to 60:40.

[Radical polymerizable compound (B)]
The curable composition may further contain the radically polymerizable compound (B). Of course, the curable composition does not have to contain the radically polymerizable compound (B).
The radically polymerizable compound (B) is a radically polymerizable compound other than the maleimide-modified compound (A).
The radically polymerizable compound (B) may be a compound having an unsaturated double bond such as styrene, a styrene polymer, acrylonitrile, (meth) acrylic acid, and (meth) acrylic acid ester.

As the above-mentioned radically polymerizable compound, various radically polymerizable compounds conventionally blended in the radically polymerizable composition can be used without particular limitation. Specific examples of the radically polymerizable compound other than the maleimide compound include the following compounds.

Examples of the monofunctional radically polymerizable compound include (meth) acrylamide, methylol (meth) acrylamide, methoxymethyl (meth) acrylamide, ethoxymethyl (meth) acrylamide, propoxymethyl (meth) acrylamide, butoxymethoxymethyl (meth) acrylamide, and the like. N-methylol (meth) acrylamide, N-hydroxymethyl (meth) acrylamide, (meth) acrylic acid, fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid, citraconic anhydride, crotonic acid, 2-acrylamide-2-methylpropanesulfonic acid, tert-butylacrylamide sulfonic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-phenoxy-2-hydroxypropyl (meth) acrylate, 2- (meth) acryloyloxy-2- Hydroxypropyl phthalate, glycerin mono (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, dimethylamino (meth) acrylate, glycidyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2 Examples thereof include 3,3-tetrafluoropropyl (meth) acrylate and half (meth) acrylate of a phthalic acid derivative. These monofunctional compounds can be used alone or in combination of two or more.

Examples of the polyfunctional radically polymerizable compound include 1,3-butanediol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,6-hexanediol di (meth) acrylate, and 1,9-. Nonanediol di (meth) acrylate, 1,10-decanediol di (meth) acrylate, 1,12-dodecanediol di (meth) acrylate, ethoxylated hexanediol di (meth) acrylate, tricyclodecanedimethanol di (meth) ) Acrylic, 2-Hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, dipentaerythritol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, dipropylene glycol di ( Meta) acrylate, tripropylene glycol di (meth) acrylate, ethoxylated neopentyl glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, poly (ethylene-propylene) glycol di (meth) acrylate, polytetramethylene glycol di (Meta) acrylate, ethoxylated bisphenol A di (meth) acrylate, propoxylated bisphenol A di (meth) acrylate, propoxylated ethoxylated bisphenol A di (meth) acrylate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) Acrylic, tetraethylene glycol di (meth) acrylate, propylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, 1,6-hexane glycol Di (meth) acrylate, trimethylolpropantri (meth) acrylate, glycerin di (meth) acrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate, pentaerythritol di (meth) Aacrylate, pentaerythritol tri (meth) acrylate, pentaerythritol tetra (meth) acrylate, dipentaerythritol penta (meth) acrylate, dipentaerythritol hexa (meth) acrylate, 2,2-bis (4- (meth) acryloxidier) Diol Xyphenyl) propane, 2,2-bis (4- (meth) acryloxypolyethoxyphenyl) propane, 2-hydroxy-3- (meth) acryloyloxypropyl (meth) acrylate, ethylene glycol diglycidyl ether di (meth) acrylate , Diethylene glycol diglycidyl ether di (meth) acrylate, diglycidyl phthalate di (meth) acrylate, glycerin triacrylate, glycerin polyglycidyl ether poly (meth) acrylate, urethane (meth) acrylate (ie, tolylene diisocyanate), trimethyl A reaction product of hexamethylene diisocyanate, hexamethylene diisocyanate, etc. and 2-vidroxyethyl (meth) acrylate, methylenebis (meth) acrylamide, (meth) acrylamide methylene ether, a condensate of polyhydric alcohol and N-methylol (meth) acrylamide, Triacrylic formal, 2,4,6-trioxohexahydro-1,3,5-triazine-1,3,5-trisethanol triacrylate, and 2,4,6-trioxohexahydro-1,3, Examples thereof include 5-triazine-1,3,5-trisethanoldiacrylate and the like. These polyfunctional compounds can be used alone or in combination of two or more.

The content of the radically polymerizable compound (B) in the curable composition is not particularly limited, but is 10% by mass or more and 70% by mass with respect to the total amount of the maleimide-modified compound (A) and the radically polymerizable compound (B). It is preferably% or less.

[Radical initiator (C)]
The curable composition comprises a radical initiator (C). The radical initiator (C) may be either a photoradical initiator (C1) or a thermal radical initiator (C2), and the photoradical initiator (C1) and the thermal radical initiator (C2) may be used in combination.

Examples of the photoinitiator (C1) include Omnirad 651, Omnirad 184, Omnirad 1173, Omnirad 2959, Omnirad 127, Omnirad 907, Omnirad 369, Omnirad 369, Omnirad 369, Omnirad 369E, Omnirad 369E, Omnirad 369E, Omnirad 369E, Omnirad 369E, Omnirad Phenon-based initiators, acylphosphine oxide-based initiators such as Omnirad TPO H, Omnirad 819 (all manufactured by IGM Resins BV), and oxime ester-based initiators such as Irgacare OXE01 and Irgacare OXE02 (all manufactured by BASF). Photopolymerizers can be mentioned.

Specific examples of the photoradical initiator (C1) include 1-hydroxycyclohexylphenylketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl]. -2-Hydroxy-2-methyl-1-propane-1-one, 1- (4-isopropylphenyl) -2-hydroxy-2-methylpropan-1-one, 1- (4-dodecylphenyl) -2- Hydroxy-2-methylpropan-1-one, 2,2-dimethoxy-1,2-diphenylethane-1-one, bis (4-dimethylaminophenyl) ketone, 2-methyl-1- [4- (methylthio) Phenyl] -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butane-1-one, 1,2-octanedione, 1- [4- [4- (Phenylthio) Phenyl]-, 2- (O-benzoyloxime) (Irgacure OXE01), Etanone-1- [9-ethyl-6- (2-methylbenzoyl) -9H-carbazol-3-yl] -1-( O-Acetyloxym (Irgacure OXE02), 2,4,6-trimethylbenzoyldiphenylphosphine oxide (Omnirad TPO H), bis (2,4,6-trimethylbenzoyl) phenylphosphine oxide (Omnirad 819), 4-benzoyl -4'-Methyldimethylsulfide, 4-dimethylaminobenzoic acid, methyl 4-dimethylaminobenzoate, ethyl 4-dimethylaminobenzoate, butyl 4-dimethylaminobenzoate, 4-dimethylamino-2-ethylhexyl benzoic acid, 4-Dimethylamino-2-isoamyl benzoic acid, benzyl-β-methoxyethyl acetal, benzyl dimethyl ketal, 1-phenyl-1,2-propandion-2- (O-ethoxycarbonyl) oxime, methyl O-benzoyl benzoate , 2,4-diethylthioxanthone, 2-chlorothioxanthone, 2,4-dimethylthioxanthone, 1-chloro-4-propoxythioxanthone, thioxanthene, 2-chlorothioxanthene, 2,4-diethylthioxanthene, 2-methylthioxanthene. , 2-Isopropylthioxanthene, 2-ethylanthraquinone, octamethylanthraquinone, 1,2-benzanthraquinone, 2,3-diphenylanthraquinone, azobisisobutyronitrile, Benoxyleperoxide, cumenehydroperoxide, 2-mercaptobenzoimider, 2-mercaptobenzoxazole, 2-mercaptobenzothiazole, 2- (O-chlorophenyl) 4,5-di (m-methoxyphenyl) -imidazolylni Acetophenone, 2-chlorobenzophenone, p, p'-bisdimethylaminobenzophenone, 4,4'-bisdiethylaminobenzophenone, 4,4'-dichlorobenzophenone, 3,3-dimethyl-4-methoxybenzophenone, benzyl, Benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-butyl ether, benzoin isobutyl ether, benzoin butyl ether, acetophenone, 2,2-diethoxyacetophenone, p-dimethylacetophenone, p-dimethylaminopropiophenone, Dichloroacetophenone, trichloroacetophenone, p-tert-butylacetophenone, p-dimethylaminoacetophenone, p-tert-butyltrichloroacetophenone, p-tert-butyldichloroacetophenone, α, α-dichloro-4-phenoxyacetophenone, thioxanthone, 2- Methylthioxanthone, 2-isopropylthioxanthone, dibenzosverone, pentyl-4-dimethylaminobenzoate, 9-phenylacrine, 1,7-bis- (9-acrydinyl) heptane, 1,5-bis- (9-acrydinyl) pentane , 1,3-bis- (9-acrydinyl) propane, p-methoxytriazine, 2,4,6-tris (trichloromethyl) -s-triazine, 2-methyl-4,6-bis (trichloromethyl) -s -Triazine, 2- [2- (5-methylfuran-2-yl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- [2- (fran-2-yl) ethenyl]- 4,6-bis (trichloromethyl) -s-triazine, 2- [2- (4-diethylamino-2-methylphenyl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- [2 -(3,4-dimethoxyphenyl) ethenyl] -4,6-bis (trichloromethyl) -s-triazine, 2- (4-methoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2 -(4-Acetophenone) -4,6-bis (trichloromethyl) -s-to Riazine, 2- (4-n-butoxyphenyl) -4,6-bis (trichloromethyl) -s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-methoxy) phenyl-s -Triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (3-bromo-4-methoxy) styryl Phenyl-s-triazine, 2,4-bis-trichloromethyl-6- (2-bromo-4-methoxy) styrylphenyl-s-triazine and the like can be mentioned. These photopolymerization initiators can be used alone or in combination of two or more. Above all, it is particularly preferable to use an oxime-based initiator in terms of sensitivity.

Examples of the thermal radical polymerization initiator (C2) include ketone peroxide (methyl ethyl ketone peroxide, cyclohexanone peroxide, etc.), peroxyketal (2,2-bis (tert-butylperoxy) butane, and 1,1-bis (tert). -Butylperoxy) cyclohexane, etc.), hydroperoxide (tert-butylhydroperoxide, cumenehydroperoxide, etc.), dialkyl peroxide (di-tert-butyl peroxide (perbutyl®) D (Nichiyu Co., Ltd.) , And di-tert-hexyl peroxide (perhexyl (registered trademark) D (manufactured by Nichiyu Co., Ltd.)), diacyl peroxide (isobutyryl peroxide, lauroyl peroxide, benzoyl peroxide, etc.), peroxy Organic peroxides of dicarbonate (diisopropylperoxydicarbonate, etc.), peroxyesters (tert-butylperoxyisobutyrate and 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, etc.)} , 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobisisobutyronitrile, 2,2'-azobis (2,4-dimethyl-4-methoxyvaleronitrile), 2 , 2'-azobis (2-methylpropion amidine) dihydrochloride, 2,2'-azobis [2-methyl-N- (2-propenyl) propion amidine] dihydrochloride, 2,2'-azobis (2-methylpropion) Amid), 2,2'-azobis [2-methyl-N- (2-hydroxyethyl) propionamide], 2,2'-azobis (2-methylpropane), 2,2'-azobis (2,4) 4-trimethylpentane) and azo compounds such as dimethyl 2,2'-azobis (2-methylpropionate)} can be mentioned.

The content of the radical initiator (C) in the curable composition is not particularly limited, but is 0.1 mass by mass with respect to 100 parts by mass of the total mass of the maleimide-modified compound (A) and the radically polymerizable compound (B). More than 10 parts by mass is preferable.

<Thiol compound (D)>
The curable composition comprises a thiol compound (D) as well as a maleimide-modified compound (A). As a result, the curable composition gives a cured product having excellent elongation and tensile strength.
The number of mercapto groups contained in the thiol compound (D) is not particularly limited. The number of mercapto groups contained in the thiol compound (D) is preferably 2 or more, more preferably 2 or more and 10 or less, still more preferably 2 or more and 6 or less, from the viewpoint of making it easier to obtain a cured product having excellent elongation and tensile strength.

Specific examples of compounds having two or more mercapto groups include 1,2-benzenedithiol, 1,3-benzenedithiol, 1,4-benzenedithiol, 1,2-bis (mercaptomethyl) benzene, and 1,3-. Bis (mercaptomethyl) benzene, 1,4-bis (mercaptomethyl) benzene, 1,2-bis (mercaptoethyl) benzene, 1,3-bis (mercaptoethyl) benzene, 1,4-bis (mercaptoethyl) benzene , 1,2,3-trimercaptobenzene, 1,2,4-trimercaptobenzene, 1,3,5-trimercaptobenzene, 1,2,3-tris (mercaptomethyl) benzene, 1,2,4- Tris (mercaptomethyl) benzene, 1,3,5-tris (mercaptomethyl) benzene, 1,2,3-tris (mercaptoethyl) benzene, 1,2,4-tris (mercaptoethyl) benzene, 1,3 5-Tris (mercaptoethyl) benzene, 2,5-toluenedithiol, 3,4-toluenedithiol, 1,3-di (p-methoxyphenyl) propane-2,2-dithiol, 1,3-diphenylpropane-2 , 2-Dithiol, phenylmethane-1,1-Dithiol, 2,4-di (p-mercaptophenyl) pentane, 1,2-bis (mercaptoethylthio) benzene, 1,3-bis (mercaptoethylthio) benzene , 1,4-bis (mercaptoethylthio) benzene, 1,2,3-tris (mercaptomethylthio) benzene, 1,2,4-tris (mercaptomethylthio) benzene, 1,3,5-tris (mercaptomethylthio) Benzene, 1,2,3-tris (mercaptoethylthio) benzene, 1,2,4-tris (mercaptoethylthio) benzene, 1,3,5-tris (mercaptoethylthio) benzene and the like can be mentioned.

Further, as the thiol compound (D) having two or more mercapto groups, a polyol having two or more hydroxyl groups can be easily obtained or synthesized, and has stability in dissolution in a curable composition. Mercapto alkanoates are preferred.
The mercapto alkanoate of a polyol having two or more hydroxyl groups may have a hydroxyl group, but preferably does not have a hydroxyl group.

The number of carbon atoms of the mercapto alkanoate that gives the mercapto alkanoate is not particularly limited, but is preferably 2 or more and 6 or less, preferably 3 or 4. Specific examples of mercaptoalkanoic acid giving mercaptoalkanoate include thioglycolic acid, 2-mercaptopropionic acid, 3-mercaptopropionic acid, 2-mercaptobutanoic acid, 3-mercaptobutanoic acid, 4-mercaptobutanoic acid, 2-. Examples thereof include mercaptopentanoic acid, 3-mercaptopentanoic acid, 4-mercaptopentanoic acid, 5-mercaptopentanoic acid, 2-mercaptohexanoic acid, 3-mercaptohexanoic acid, 4-mercaptohexanoic acid, and 5-mercaptohexanoic acid.
Of these, 2-mercaptopropionic acid and 3-mercaptobutanoic acid are preferred.

The polyol giving the mercapto alkanoate may contain aromatic groups.
Examples of the aromatic group-free polyol include ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, and 1,7-heptanediol. , 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, 1,4-cyclohexanediol , 1,3-Cyclohexanediol, 1,2-Cyclohexanediol, 1,4-Cyclohexanedimethanol, Bisphenol A hydride, Glycerin, Diglycerin, Triglycerin, Trimethylolethane, Trimethylolpropane, Pentaerythritol, Dipentaerythritol , Sorbitol, mannitol, sorbitan, sucrose, glucose, mannose, methyl glucoside, tris (2-hydroxyethyl) isocyanuric acid and the like.
Aromatic polyols include benzenediols such as hydroquinone, resorcinol, and catechol; benzenetriols such as fluoroglucol, pyrogallol, and 1,2,4-benzenetriol; 1,2-naphthalenediol, 1,3-naphthalenediol. , 1,4-Naphthalenediol, 1,5-naphthalenediol, 1,6-naphthalenediol, 1,7-naphthalenediol, 1,5-naphthalenediol, 2,3-naphthalenediol, 2,6-naphthalenediol, And naphthalene diols such as 2,7-naphthalendiol; 1,4,5-naphthalentriol, 1,2,4-naphthalentriol, 1,3,8-naphthalentriol, and 1,2,7-naphthalentriol and the like. Naphthalentriol; bisphenols such as bisphenol A, bisphenol AP, bisphenol AF, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol S, and bisphenol Z; 3,3', 4,4'-tetrahydroxy Examples thereof include biphenyl and tetrahydroxybiphenyl such as 3,3', 5,5'-tetrahydroxybiphenyl; calix arene; novolak resins such as phenol novolac, cresol novolak, and naphthol novolak.

Among the above polyols, ethylene glycol, 1,3-propanediol, propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, dipropylene glycol, glycerin, and di Glycerin, trimethylolethane, trimethylolpropane, pentaerythritol, dipentaerythritol, and tris (2-hydroxyethyl) isocyanuric acid are preferred, with 1,4-butanediol, trimethylolethane, trimethylolpropane, pentaerythritol, and tris. (2-Hydroxyethyl) isocyanuric acid is more preferred.

Examples of the polyol mercaptoalkanoate described above include 1,4-butanedioldi (2-mercaptopropionate), 1,4-butanedioldi (3-mercaptobutanoate), and trimethylolethanetri (2-). Mercaptopropionate), trimethylolethanetri (3-mercaptobutanoate), trimethylolpropanetri (2-mercaptopropionate), trimethylolpropanetri (3-mercaptobutanoate), pentaerythritol tetra (2) -Mercaptopropionate), pentaerythritol tetra (3-mercaptobutanoate), trimethylolethane (2-hydroxyethyl) isocyanurate tri (2-mercaptopropionate), and trimethylolethane (2-hydroxyethyl) isocyanurate tri (2-hydroxyethyl) isocyanurate tri ( 3-mercaptobutanoate) is preferred, 1,4-butanedioldi (3-mercaptobutanoate), trimethylolethanetri (3-mercaptobutanoate), trimethylolpropanetri (3-mercaptobutanoate). ), Pentaerythritol tetra (3-mercaptobutanoate) and tris (2-hydroxyethyl) isocyanurate tri (3-mercaptobutanoate) are more preferred.

The amount of the thiol compound (D) used is not particularly limited as long as it does not impair the object of the present invention. The amount of the thiol compound (D) used is preferably 0.1 part by mass or more and 20 parts by mass or less with respect to 100 parts by mass in total of the mass of the maleimide-modified compound (A) and the mass of the radically polymerizable compound (B). , 0.5 parts by mass or more and 15 parts by mass or less is more preferable, and 1 part by mass or more and 12 parts by mass or less is further preferable.

<Protonic acid (E)>
The curable composition preferably contains a protonic acid (E). When the curable composition contains the thiol compound (D) together with the maleimide-modified compound (A), the curable composition may easily change in viscosity with time. However, when the curable composition contains a protonic acid (E) together with the thiol compound (D), the stability of the curable composition over time can be enhanced. Here, the protonic acid refers to a compound capable of releasing ^{proton H +.}
When the maleimide-modified compound (A) has an acidic group that acts as a protonic acid such as a carboxy group or a phenolic hydroxyl group, the curable composition containing the maleimide-modified compound (A) contains the protonic acid (E). It shall include.

The protonic acid may be an organic acid or an inorganic acid, and an organic acid is preferable.
Specific examples of organic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, isovaleric acid, acrylic acid, methacrylic acid, oxalic acid, phthalic acid, benzoic acid, salicylic acid, 4-hydroxybenzoic acid, lactic acid, and citrus. Acids, tartaric acid, malonic acid, malic acid, succinic acid, glycolic acid, glutamic acid, aspartic acid, maleic acid, caproic acid, capric acid, myristic acid, stearic acid, palmitic acid, pyruvate, ascorbic acid, adipic acid, phenol, Examples thereof include 1-naphthol, 2-naphtholmethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, methylphosphonic acid, ethylphosphonic acid, and phenylphosphonic acid.
Specific examples of the inorganic acid include hydrochloric acid, hydrobromic acid, sulfuric acid, nitric acid, phosphoric acid and the like.

The amount of the protonic acid (E) used is not particularly limited as long as it does not impair the object of the present invention. The amount of the protonic acid (E) used is preferably 0.1 part by mass or more and 5 parts by mass or less with respect to 100 parts by mass in total of the mass of the maleimide-modified compound (A) and the mass of the radically polymerizable compound (B). , 0.2 parts by mass or more and 3 parts by mass or less is more preferable, and 0.5 parts by mass or more and 1.5 parts by mass or less is further preferable.

<Organic solvent (S)>
The curable composition usually contains an organic solvent (S). The type of the organic solvent (S) is not particularly limited as long as it does not impair the object of the present invention, and can be appropriately selected from the organic solvents conventionally used in the curable composition.

Specific examples of the organic solvent (S) include ketones such as acetone, methyl ethyl ketone, cyclohexanone, methyl isoamyl ketone, and 2-heptanone; ethylene glycol, ethylene glycol monoacetate, diethylene glycol, diethylene glycol monoacetate, propylene glycol, and propylene glycol monoacetate. , Propropylene glycol monomethyl ether acetate, dipropylene glycol, monomethyl ether of dipropylene glycol monoacetate, monoethyl ether, monopropyl ether, monobutyl ether, monophenyl ether and other polyvalent alcohols and derivatives thereof; cyclic ether such as dioxane. Classes: ethyl formate, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, methyl acetoacetate, ethyl acetoacetate, ethyl pyruvate, ethyl ethoxyacetate, methyl methoxypropionate, ethyl ethoxypropionate, Methyl 2-hydroxypropionate, ethyl 2-hydroxypropionate, ethyl 2-hydroxy-2-methylpropionate, methyl 2-hydroxy-3-methylbutanoate, 3-methoxybutyl acetate, 3-methyl-3-methoxybutyl acetate Esters such as; aromatic hydrocarbons such as toluene and xylene; and the like. These may be used alone or in combination of two or more.

The content of the organic solvent (S) is not particularly limited as long as it does not impair the object of the present invention. It is preferable to use the organic solvent (S) in the range where the solid content concentration of the curable composition is 30% by mass or more and 70% by mass or less.

[Other additives]
The curable composition may further contain a maleimide curing agent in order to improve curability, and may further contain a surfactant in order to improve coatability, defoaming property, leveling property and the like. Good.
Examples of the maleimide curing agent include diamines, low-polarity polyfunctional allylphenol resins (for example, FATC-809 and FATC-AE (both manufactured by Gunei Chemical Industries, Ltd.)), allyl compounds such as allyl ethers, and propenylated biphenylene resins. (For example, 1-propenyl compound having a 1-propenyl group such as BPN (manufactured by Gunei Chemical Industry Co., Ltd.)), and a benzoxazine compound can be mentioned.
As the surfactant, for example, a fluorine-based surfactant or a silicone-based surfactant is preferably used.
Specific examples of fluorine-based surfactants include BM-1000 and BM-1100 (all manufactured by BM Chemie), Megafuck F142D, Megafuck F172, Megafuck F173, and Megafuck F183 (all manufactured by Dainippon Ink and Chemicals Co., Ltd.). , Florard FC-135, Florard FC-170C, Florard FC-430, Florard FC-431 (all manufactured by Sumitomo 3M), Surfron S-112, Surfron S-113, Surfron S-131, Surfron S- Commercially available fluorine-based surfactants such as 141, Surflon S-145 (all manufactured by Asahi Glass Co., Ltd.), SH-28PA, SH-190, SH-193, SZ-6032, SF-8428 (all manufactured by Toray Silicone Co., Ltd.) However, the present invention is not limited to these.
Silicone-based surfactants include unmodified silicone-based surfactants, polyether-modified silicone-based surfactants, polyester-modified silicone-based surfactants, alkyl-modified silicone-based surfactants, aralkyl-modified silicone-based surfactants, and aralkyl-based silicone-based surfactants. A reactive silicone-based surfactant or the like can be preferably used.
As the silicone-based surfactant, a commercially available silicone-based surfactant can be used. Specific examples of commercially available silicone-based surfactants include Painted M (manufactured by Toray Dow Corning), Topica K1000, Topica K2000, Topica K5000 (all manufactured by Takachiho Sangyo Co., Ltd.), XL-121 (polyester-modified silicone-based). Surfactants, manufactured by Clariant, BYK-310 (polyester-modified silicone-based surfactants, manufactured by Big Chemie) and the like.

The curable composition may contain an antioxidant. The antioxidant is not particularly limited, and conventionally known antioxidants can be used. For example, a hindered phenol-based antioxidant, a hindered amine-based antioxidant, a phosphorus-based antioxidant, and a sulfur-based antioxidant can be used. And so on.

The curable composition may contain a polymerization inhibitor in order to appropriately prevent polymerization during the reaction. The polymerization inhibitor is not particularly limited, and conventionally known polymerization inhibitors can be used, and examples thereof include methquinone, hydroquinone, methylhydroquinone, p-methoxyphenol, pyrogallol, tert-butylcatechol, and phenothiazine.

When an insulating film is formed by using a curable composition, the curable composition includes a metal wiring, a substrate for an electric / electronic device having the metal wiring, and an insulating film formed by using the curable composition. In order to improve the adhesiveness of the material, an adhesiveness improving agent may be contained. The adhesion improver is not particularly limited, and conventionally known adhesion improvers can be used, and examples thereof include benzotriazole and the like.

[Method for preparing curable composition]
The curable composition is prepared by mixing and stirring each of the above components by a usual method. Examples of an apparatus that can be used when mixing and stirring each of the above components include a dissolver, a homogenizer, and a three-roll mill. After uniformly mixing each of the above components, the obtained mixture may be further filtered using a mesh, a membrane filter or the like.

Further, the curable composition is a multi-drug mixed type curable composition composed of two or more multi-drugs containing a first agent containing a maleimide-modified compound (A) and a second agent containing a thiol compound (D). It is also preferable to use a composition. When the maleimide-modified compound (A) and the thiol compound (D) coexist in the curable composition, the curable composition may easily change with time. However, in the case of the above-mentioned multi-drug mixed curable composition, such a problem of aging does not occur.

The above-mentioned multi-drug mixed curable composition may be, for example, a multi-drug mixed composition of three or more agents, which further contains a third agent containing a radical generator (C). However, since the mixing operation at the time of use is easy, the multi-drug mixed curable composition includes a first agent containing a maleimide-modified compound (A) and a second agent containing a thiol compound (D). A two-agent mixed curable composition comprising the above is preferable.
Regarding the two-agent mixed curable composition, the first agent containing the maleimide-modified compound (A) and the second agent containing the thiol compound (D) are the maleimide-modified compound (A) and the thiol compound (D), respectively. ) May be optionally contained in one or more kinds of components other than). In the two-agent mixed curable composition, either the first agent or the second agent contains a radical generator (C).

≪How to form an insulating film≫
An insulating film is formed using the above curable composition.
The method of forming the insulating film is
A coating process in which a curable composition is applied to the insulating film forming portion to form a coating film, and
Includes a curing step, which cures the coating film.

Preferably, the curable composition can be used to form an insulating film that insulates the metal wiring in an electrical / electronic device having the metal wiring.

In the method of forming the insulating film, for example, the curable composition is applied to at least the insulating film forming portion on the substrate for an electric / electronic device having metal wiring to form the coating film.
As a method for applying the curable composition, a spin coating method, a slit coating method, a roll coating method, a screen printing method, an inkjet method, an applicator method and the like can be adopted. When a printing method such as a screen printing method or an inkjet method is applied, it is possible to apply the curable composition only to the portion where the insulating film is punished.

The thickness of the coating film is not particularly limited, but is preferably 0.5 μm or more, more preferably 0.5 μm or more and 300 μm or less, particularly preferably 1 μm or more and 150 μm or less, and most preferably 3 μm or more and 50 μm or less.

Then, if necessary, the coating film is dried or prebaked. The pre-baking conditions vary depending on the type, blending ratio, coating film thickness, etc. of each component in the curable composition, but are usually 70 ° C. or higher and 200 ° C. or lower, preferably 80 ° C. or higher and 150 ° C. or lower, for 2 minutes or longer and 120. It is less than a minute.

When the curable composition contains a photoradical generator (C1), the coating film is irradiated (exposed) with active light or radiation, for example, ultraviolet rays or visible light having a wavelength of 300 nm or more and 500 nm or less. The entire surface of the coating film may be exposed, or regioselective exposure (pattern exposure) may be performed by a method such as exposing active rays or radiation through a mask having a predetermined pattern.
Upon exposure, the maleimide-modified compound (A) and the radically polymerizable compound (B), which are polymerization components, are polymerized to form an insulating film. As a result, for example, an insulating film is formed on a substrate for an electric / electronic device having metal wiring.

As the radiation source, a low-pressure mercury lamp, a high-pressure mercury lamp, an ultra-high-pressure mercury lamp, a metal halide lamp, an argon gas laser, or the like can be used. Further, the radiation includes microwaves, infrared rays, visible rays, ultraviolet rays, X-rays, γ-rays, electron beams, proton beams, neutron beams, ion rays and the like. Dose of radiation varies depending on the film thickness and the like of the composition and the coating film of the curable composition, for example, in the case of ultra-high pressure mercury lamp used is 100 mJ / cm ² or more 10000 mJ / cm ² or less. Further, the radiation may include a light beam that activates the radical initiator (C) in order to generate a radical.

In the case of regioselective exposure, the exposed coating film is developed according to a conventionally known method, and an unnecessary portion is dissolved and removed to form an insulating film having a predetermined shape. At this time, the organic solvent (S) or an alkaline aqueous solution can be used as the developing solution. For example, when the above-mentioned maleimide-modified compound (A) has an alkali-soluble group such as a carboxy group or a phenolic hydroxyl group, development with an alkaline aqueous solution is possible.

Examples of the alkaline aqueous solution used as the developing solution include sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, aqueous ammonia, ethylamine, n-propylamine, diethylamine, di-n-propylamine, and triethylamine. , Methyldiethylamine, dimethylethanolamine, triethanolamine, tetramethylammonium hydroxide (tetramethylammonium hydroxide), tetraethylammonium hydroxide, pyrrole, piperidine, 1,8-diazabicyclo [5,4,0] -7-undecene , 1,5-diazabicyclo [4,5,0] -5-nonane and other alkaline aqueous solutions can be used. Further, an aqueous solution obtained by adding an appropriate amount of a water-soluble organic solvent such as methanol or ethanol or a surfactant to the above-mentioned aqueous solution of alkalis can also be used as a developing solution.

The developing time varies depending on the composition of the curable composition, the film thickness of the coating film, and the like, but is usually between 1 minute and 30 minutes or less. The developing method may be any of a liquid filling method, a dipping method, a paddle method, a spray developing method and the like.

After development, for example, washing with running water is performed for 30 seconds or more and 90 seconds or less, and the mixture is dried using an air gun, an oven, or the like.

In this way, for example, an insulating film patterned in a desired shape is formed on a substrate for an electric / electronic device having metal wiring.

In the above, an example is shown in which the maleimide-modified compound (A) and the radically polymerizable compound (B), which are polymerization components, are polymerized by exposure to form an insulating film. When the curable composition contains a thermal radical generator (C2), the maleimide-modified compound (A) and the radically polymerizable compound (B), which are polymerization components, may be polymerized by heating to form an insulating film.

The formed insulating film has a low dielectric constant and a low dielectric loss tangent, and is therefore suitable as an insulating film for electrical / electronic devices having metal wiring for high frequency applications. For example, it can be used as an insulating film for an electric / electronic device having a metal wiring for a 5G communication band candidate frequency of 3 GHz or more and 30 GHz or less and a millimeter wave band frequency of 30 GHz or more and 300 GHz or less. Further, since the formed insulating film has excellent heat resistance, it is suitable for applications in which a member such as wiring is further formed by heating after forming the insulating film.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to these Examples.

[Preparation Example 1]
As the unmodified polyphenylene ether resin, a polyphenylene ether resin having a phenolic hydroxyl group terminal having the following structure (SA90, manufactured by SABIC Innovative Plastics) was used.

166 parts by mass of an unmodified polyphenylene ether resin and 47.2 parts by mass of a carboxylic acid having a maleimide group having the following structure were added to 1184 parts by mass of dichloroethane.

After adding 40.9 parts by mass of diisopropylcarbodiimide and 0.25 parts by mass of dimethylaminopyridine to the reaction solution, a modification reaction of the terminal phenolic hydroxyl group was carried out at 5 ° C. for 8 hours. After the reaction, the reaction solution was filtered and reprecipitated with acetonitrile to obtain 145 parts by mass of a maleimide-modified polyphenylene ether resin A1 in which the phenolic hydroxyl groups at both ends of the unmodified polyphenylene ether resin were modified based on the following formula. The polystyrene-equivalent mass average molecular weight (Mw) of the maleimide-modified polyphenylene ether resin P1 measured by gel permeation chromatography (GPC) was 7,000.

[Preparation Example 2]
As the resin A2, a resin in which the amino group in the copolymer of styrene and 4-aminostyrene was modified with maleimide was prepared.
72.8 parts by mass of the copolymer in which the copolymerization ratio of styrene and 4-aminostyrene is 80/20 (molar standard) as styrene / 4-aminostyrene (molar standard) and oxo represented by the following formula 41 parts by mass of norbornene anhydride was dissolved in 300 parts by mass of tetrahydrofuran, and the mixture was stirred under a nitrogen atmosphere for 4 hours.

Next, 61 parts by mass of carbonyldiimidazole was added to the reaction solution, and then the reaction solution was stirred for 6 hours. Then, the reaction solution was added dropwise to 1500 parts by mass of heptane to recover a polymer having the following structure precipitated. The number in the lower right of the parentheses in each structural unit in the following structural formula represents the content (mol%) of the structural unit in each resin.

The obtained polymer having the above structure was made into a 20% by mass toluene solution, and the mixture was stirred for 4 hours while refluxing. Then, by reprecipitation with heptane, 17.8 parts by mass of a solid resin A2 having the following structure was obtained.
^The maleimide structure was confirmed from the carbonyl peak and the double bond peak in 13 C NMR. ^{The measurement solvent for 13} C NMR was acetone-d6.
Moreover, the mass average molecular weight (Mw) of the obtained resin A2 was determined by gel permeation chromatography (GPC) in terms of polystyrene. The mass average molecular weight (Mw) of the resin A2 was 15,000.

<Preparation of curable composition>
[Examples 1 to 14 and Comparative Examples 1 to 4]
In Examples 1 to 14, the above resins A1 and A2 and the following A3 were used as the maleimide-modified compound (A).
A3 is BMI-689 (manufactured by Designer molecules).

In Examples 1 to 14 and Comparative Examples 1 to 4, the following C1 and C2 were used as the radical initiator (C).
C1: Irgacure OXE02 (manufactured by BASF)
C2: Perhexyl D (manufactured by NOF CORPORATION)

In Examples 1 to 14, the following D1 and D2 were used as the thiol compound (D).
D1: Pentaerythritol tetra (3-mercaptobutanoate)
D2: Tris (2-hydroxyethyl) trichloroisocyanuric acid (3-mercaptobutanoate)

In Examples 1 to 8 and Examples 11 to 14, the following E1 to E3 were used as the protonic acid (E).
E1: Phenylphosphonic acid E2: Satilic acid E3: Malonic acid

In Examples 1 to 14 and Comparative Examples 1 to 4, the following F1 was used as an additive.
F1: Irganox 1010 (manufactured by BASF)
F2: FATC-809 (maleimide curing agent, low-polarity polyfunctional allylphenol resin (manufactured by Gun Ei Chemical Industry Co., Ltd.))
F3: FATC-AE (maleimide curing agent, low-polarity polyfunctional allylphenol resin (manufactured by Gun Ei Chemical Industry Co., Ltd.))

Maleimide-modified compound (A), radical initiator (C), thiol compound (D), protonic acid (E), additive, and surfactant of the types and amounts shown in Tables 1 and 2, respectively. 0.05 parts by mass (BYK310, manufactured by Big Chemie) was dissolved in propylene glycol monomethyl ether acetate (PGMEA) so that the solid content concentration was 40% by mass, and the curable composition of each Example and Comparative Example was obtained. I got something.

<Evaluation>
Using the obtained curable composition, the film forming property, the photolithographic property, the dielectric constant, the dielectric loss tangent, and the heat resistance were evaluated according to the following methods. The evaluation results are shown in Tables 1 and 2.
[Film film properties and photolithography characteristics]
The curable compositions of Examples and Comparative Examples were applied onto a Si substrate having a diameter of 200 mm to form a coating film. The coating film was then prebaked (PAB) at 80 ° C. for 200 seconds. The film thickness of the coating film after prebaking was 11 μm. After pre-baking, and at 4400mJ / cm ² or less exposure dose 100 mJ / cm ² or more using a mask and an exposure apparatus Prisma GHI5452 hole pattern capable of forming a circular opening with a diameter of 30 [mu] m (manufactured by Ultratech Co., Ltd.), pattern exposure with ghi ray did. The focal point was 0 μm (coating film surface).
The substrate was then placed on a hot plate and exposed and then heated (PEB) at 90 ° C. for 1.5 minutes. Then, the exposed coating film was immersed in propylene glycol monomethyl ether acetate (PGMEA) at 60 ° C. for 60 seconds. Then, it was blown with nitrogen and heated at 180 ° C. for 1 hour in a nitrogen atmosphere to obtain a pattern (insulating film).
The surface of the coating film before prebaking was observed with a scanning electron microscope to evaluate the film forming property. Specifically, the case where no cracks and / or crystals were observed on the surface of the pattern, the pattern had no tack (stickiness), and the contained components were compatible with each other and was transparent was marked with ◯. Further, a is the case where cracks are observed on the pattern surface, b is the case where crystals are observed on the pattern surface, c is the case where the pattern surface is tacky (sticky), and the contained components are not compatible and opaque. The case where was was set as d, and the case corresponding to at least one of a to d was set as x.
In addition, the surface and cross section of the obtained pattern (insulating film) were observed with a scanning electron microscope to evaluate the photolithography characteristics. Specifically, in the above-mentioned exposure amount range, the case where the condition for forming an opening having a diameter of 30 μm was present was evaluated as ◯, and the case where the condition for forming an opening with a diameter of 30 μm did not exist was evaluated as ×. ..

[Permittivity and dielectric loss tangent]
The curable compositions of Examples and Comparative Examples were applied onto a Si substrate having a diameter of 200 mm to form a coating film. The coating film was then prebaked (PAB) at 80 ° C. for 200 seconds. The film thickness of the coating film after prebaking was 11 μm. After prebaking, the entire surface was exposed with a ghi line at an ^{exposure amount of 4400 mJ / cm 2} using an exposure apparatus Prisma GHI5452 (manufactured by Ultratech). The focal point was 0 μm (coating film surface). Then, the surface of the coating film was blown with nitrogen and heated at 180 ° C. for 1 hour in a nitrogen atmosphere to obtain a sample.
The permittivity (ε) and dielectric loss tangent (tan δ) of the obtained sample are described in the IEICE Technical Report vol. 118, no. 506, MW2018-158, pp. 13-18, March 2019. Examination of Milliwave Complex Dielectric Permittivity Evaluation of Photosensitive Insulating Film by Cylindrical Cavity Resonator Method ”(Kohei Takahagi (Utsunomiya University), Kazuaki Ebisawa (Tokyo Oka Kogyo Co., Ltd.), Yoshinori Kogami (Utsunomiya University), Takashi Shimizu ( It was measured by the method described in Utsunomiya University)). Using a network analyzer HP8510C (manufactured by Keysight Co., Ltd.), measurement was performed by a cavity resonator method under the conditions of room temperature 25 ° C., humidity 50%, frequency 36 GHz, and sample thickness 10 μm.
The dielectric constant was evaluated as ◯ when the dielectric constant value was less than 3.00 and x when it was 3.00 or more.
The dielectric loss tangent was evaluated as ◯ when the dielectric loss tangent value was less than 0.01 and x when the dielectric loss tangent value was 0.01 or more.

[Heat-resistant]
For the sample obtained by the same method as the item of [Dielectric constant and dielectric loss tangent], the peak top temperature (° C.) of tan δ measured using a dynamic viscoelasticity measuring device Rheogel-E4000 (manufactured by UBM Co., Ltd.) was measured. , Glass transition point (Tg) (DMA method). The measurement conditions were measurement mode: tensile mode, frequency: 10 Hz, heating rate: 5 ° C./min, measurement temperature range: 40 to 300 ° C., sample shape: length 50 mm, width 5 mm, thickness 10 μmm.
The heat resistance was evaluated as ◯ when the Tg was 150 ° C. or higher and x when the Tg was lower than 150 ° C.

[Elongation and tensile strength]
A strip-shaped test piece having a width of 1 cm and a length of 5 cm was cut out from the film obtained by peeling the film from the Si substrate. Using the obtained test piece and EZ-test (manufactured by Shimadzu Corporation), a tensile test was performed at a distance between chucks of 2 cm and a tensile speed of 1 mm / min, and elongation and tensile strength were measured. The distance between the chucks at the breaking point was calculated as the elongation.
Regarding the elongation, the case where the elongation measured by the above method was 8% or more was evaluated as ◯, and the case where the elongation was less than 8% was evaluated as x.
Regarding the tensile strength, the case where the tensile strength measured by the above method was 90 MPa or more was evaluated as ◯, and the case where the tensile strength was less than 90 MPa was evaluated as x.

[Storage stability]
The curable composition of each example was stored at room temperature for 1 week, and the case where it did not gel was evaluated as ◯, and the case where it was gelled was evaluated as x.

According to Examples 1 to 14, a curable composition containing a maleimide-modified compound (A), a radical generator (C), and a thiol compound (D) is excellent in film-forming property and photolitho property. It can be seen that a cured film having excellent dielectric properties, heat resistance, elongation, and tensile strength that can be suitably used as an insulating film can be formed.
On the other hand, according to Comparative Examples 1 to 4, when the curable composition contained the maleimide-modified compound (A) but did not contain the thiol compound (D), the cured film had excellent elongation and excellent tensile strength. It turns out that it is difficult to achieve both strength and strength.
Further, from the comparison between Examples 9 and 10 and other Examples, when the curable composition contains the thiol compound (D) together with the maleimide-modified compound (A), gelation over time is likely to occur. It can be seen that the addition of the protonic acid (E) to the curable composition suppresses the gelation over time.

Claims (13)

It contains a maleimide-modified compound (A), a radical generator (C), and a thiol compound (D).
The maleimide-modified compound (A) has the following formula (a1):

It has one or more groups represented by
The group represented by the formula (a1) is bonded to a carbon atom in the aliphatic hydrocarbon group or the aromatic group in the maleimide-modified compound (A).
In the above formula (a1), R ^a01 and R ^a02 independently represent a hydrogen atom, an alkyl group having 1 or more and 6 or less carbon atoms, a cycloalkyl group having 3 or more and 8 or less carbon atoms, or 6 or more and 12 carbon atoms. A curable composition which is the following aryl group. The curable composition according to claim 1, wherein the radical generator (C) contains a photoradical generator (C1) and can be cured by exposure. The curable composition according to claim 1, which comprises a protonic acid (E). The curable composition according to claim 3, wherein the radical generator (C) contains a photoradical generator (C1) and can be cured by exposure. The curable composition according to any one of claims 1 to 4, wherein the maleimide-modified compound (A) is a maleimide-modified polyphenylene ether resin (A1-1). The curable composition according to any one of claims 1 to 5, wherein the thiol compound (D) is a mercapto alkanoate of a polyol having two or more hydroxyl groups. The curable composition according to claim 6, wherein the thiol compound (D) is 3-mercaptobutanoate of the polyol. Claimed to be a multi-drug mixed curable composition comprising two or more multi-drugs containing the first agent containing the maleimide-modified compound (A) and the second agent containing the thiol compound (D). Item 2. The curable composition according to any one of Items 1 to 7. The curable composition according to any one of claims 1 to 8, which is used for forming an insulating film. A cured product of the curable composition according to any one of claims 1 to 9. A coating step of applying the curable composition according to any one of claims 1 to 9 to form a coating film at an insulating film forming portion.
A method for forming an insulating film, which comprises a curing step of curing the coating film. The method for forming an insulating film according to claim 11, wherein the curable composition contains a photoradical generator (C1) as the radical generator (C), and the coating film is cured by exposure. The exposure to the coating film is regioselective.
The method for forming an insulating film according to claim 12, further comprising a developing step of developing the exposed coating film with a developing solution.